The invention relates to a suction dredger, comprising a vessel and a suspension conveying conduit provided with a pump and having a nozzle suspended by means of at least one cable of a lifting device on the vessel, said lifting device mainly consisting of a winch drum provided with control means for hauling and veering cable in order to adjust the depth of the nozzle with respect to the vessel, and consisting of a cable length variator comprising at least one piston which is movable in a cylinder against the pressure of a fluid and winch has a travel corresponding with the variations of the cable length as a result of sea level movement. Such a suction dredge is known.
This known suction dredger is with a large sea level movement not suitable for sucking up sand from the ground with a nozzle which is deeply inserted into the ground, because in case the nozzle sticks in the ground, with an upward movement of the vessel the ground exerts a downward ground reaction upon the nozzle, owing to which the cable may break or another part of the suction dredger may be damaged.